Climate change poses a serious threat to many bird species around the world. As global temperatures rise, birds’ natural habitats are being altered and destroyed. Their traditional migration patterns are being disrupted, their food sources are shifting or declining, and their breeding and nesting cycles are being affected. While some birds may be able to adapt to the changes brought on by climate change, many are unable to do so quickly enough and are seeing rapid population declines. Understanding which birds are most vulnerable to climate change allows us to target conservation efforts towards protecting those species most at risk.
How does climate change threaten birds?
There are several ways in which climate change harms birds:
- Habitat loss – Rising sea levels, drought, wildfires, and pests are destroying or altering natural habitats for birds. Coastal birds are losing nesting areas to encroaching seas while forest birds are losing tree cover to fires and disease.
- Shifting natural resources – Increases in temperature and changes in rainfall patterns are shifting when and where food sources like insects and fruit will be available. Birds dependent on seasonal abundance of resources may find little to eat.
- Disrupted migration patterns – Some birds rely on environmental cues and conditions to trigger migration to breeding grounds. As seasonal weather shifts, migration timing may be disrupted.
- Mismatch with prey/plants – The timing of migration and breeding must align with peak food abundance for young. If food sources peak at different times due to climate change, it can spell disaster for nesting success.
- Extreme weather – More frequent and intense storms, floods, heat waves and other weather extremes may directly threaten birds and their nesting sites.
- Weakened habitat resilience – Habitats normally resilient to some environmental variation may lose this resilience as climate change stresses resources like water availability and plant growth beyond normal levels.
All of these impacts combine to potentially catastrophic effects on birds. Scientists have identified certain traits that may make some families and species particularly vulnerable compared to others.
Which types of birds are most threatened?
According to scientific studies and assessments, the following types of birds face higher risk from climate change compared to other groups:
- Specialist species – Birds with specific habitat needs, restricted ranges or very specialized diets tend to fare worse when conditions change since they cannot easily switch to alternates.
- Coastal birds – Sea level rise and increasing storms put shorebirds and other coastal species at very high risk of losing critical nesting areas and food supplies.
- Long-distance migrants – Birds that travel thousands of miles between wintering and breeding grounds appear very vulnerable, perhaps due to the extensive habitat changes they encounter and high energy demands of migration.
- Arctic breeders – The Arctic is warming at twice the global rate so birds reliant on its wetlands and tundra for egg-laying and rearing young are rapidly losing suitable habitat.
- Alpine species – Populations breeding at high elevations face pressures as tree/shrub lines shift upslope and cold-adapted prey species decline with warming.
- Hawaiian endemics – Over 70 endangered bird species are endemic to Hawaii’s islands where rising temperatures aid the spread of mosquito-borne diseases like avian malaria in higher elevations that were previously safe.
- Wetland birds – Loss of wetlands from drought and sea level rise hits water-dependent birds hard, from herons to grebes to rails.
Scientists use a number of criteria to assess a bird species’ vulnerability to climate change. This includes factors like reproductive rates, genetic diversity, habitat flexibility, and geographic distribution. Combining this data allows them to pinpoint which species are highest priority for monitoring and protection from continued warming.
Examples of at-risk bird species
Many individual bird species around the world are already experiencing population declines linked to climate change impacts. Here are some prominent examples:
Puffin
Atlantic puffins breed in burrows on cliffs and offshore islands across the northern Atlantic. They have very specific temperature needs – bringing food like fish back to chicks waiting in burrows. Their numbers have dropped up to 80% in the past decade as sea surface warming has reduced food supplies. Rising ocean acidity may also diminish availability of shellfish.
Emperor penguin
Emperor penguins breed exclusively in Antarctica during the winter when sea ice provides a platform for rearing chicks. Climate models project extensive decline in Antarctic sea ice over the next century, which will dramatically shrink penguin populations by eliminating breeding habitat.
Whooping crane
This North American crane declined to just 21 individuals in 1941. Despite significant conservation efforts, climate change impacts now endanger the recovery of whooping cranes. Their migration route across the Great Plains is projected to see more frequent droughts and extreme weather events that reduce wetland habitat.
Yellow warbler
Yellow warblers are a migrant songbird that winters in Central and northern South America and breeds across North America. Models indicate rising temperatures will severely reduce the amount of climatically suitable habitat for this warbler both in its breeding grounds and along its migration route through Mesoamerica.
Greater sage-grouse
This iconic western grouse relies on large expanses of sagebrush. Habitat loss combined with climate factors like increased fire risk and invasive species encroachment has caused its population to decline two-thirds from historic levels. Higher temperatures and altered precipitation could continue shrinking sagebrush areas suitable for sage-grouse.
Tuamotu sandpiper
This small shorebird is found only on a tiny chain of islands in French Polynesia. Rising sea levels already diminished their nesting habitat on these low-lying coral islands. Continued ocean rise from warming temperatures could eliminate remaining nesting sites, putting this species at very high risk of extinction.
These examples help illustrate how certain traits – like habitat specificity, narrow migration routes, reliance on cold climates, and sensitivity to ocean changes – disproportionately predispose certain bird species to climate-related declines. Urgent conservation planning and action is needed to improve their chances of survival in a warming world.
What regions face the most risk of bird loss from climate change?
Certain geographic regions stand out as facing high risk of substantial bird loss driven by climate change factors. These include:
- The Arctic – Rapid warming and loss of tundra threatens shorebirds, seabirds, and alpine breeders like the snow bunting and common eider.
- Small islands – Habitat loss from rising seas imperils many island endemics that exist nowhere else, especially in Hawaii and the South Pacific.
- Coasts worldwide – Coastal birds everywhere from gulls to terns to migratory sandpipers face severe nesting habitat loss from sea level rise and erosion.
- The tropics – Deforestation and warming already pressure tropical montane species in regions like Costa Rica’s cloud forests.
- Western mountains – Alpine species like ptarmigan and rosy finches decline as warming shrinks cold mountain habitats.
- Eastern forests – Songbirds like the wood thrush face warming temperatures unsuited for their forest breeding grounds.
- Southwestern deserts – Drought and reduced snowpack threatens species like black-chinned sparrows as landscapes dry out.
No area is immune from climate change impacts on birds. But understanding the geographic hotspots with concentrations of highly vulnerable species can help prioritize and target conservation actions where they are likely to have the biggest impact.
What conservation efforts help threatened birds adapt to climate change?
While the challenges climate change poses to birds are great, all hope is not lost. Conservationists worldwide are working hard to implement strategies and programs that can give species a better chance by increasing resilience and adaptive capacity. Some important initiatives include:
- Habitat protection and restoration – Preserving existing high quality habitat and improving degraded areas provides birds with the healthiest possible spaces to nest and feed as conditions change.
- Maintaining migration corridors – Keeping migration pathways intact and minimizing obstacles allows birds to adjust routes as food/habitat shift so they can still reach breeding sites.
- Controlling invasive species – Removing predators and competitors that might benefit from climate change helps limit additional pressures on native birds.
- Assisted migration – Human-facilitated transfer to more suitable habitat just outside current range may help some species keep pace with shifting conditions.
- Captive breeding/rearing – For critically endangered species, captive populations provide a safeguard against extinction and can be used to restock wild areas.
- Regional collaboration – Coordinating efforts across jurisdictions and countries ensures protection measures span the full ranges of migratory birds.
- Monitoring and research – Continued study of climate impacts and responses informs adaptation strategies and helps set priorities for conservation spending.
Using approaches like these tailored to specific situations gives the most imperiled species a fighting chance. But preventing the worst climate change scenarios via global emissions reduction remains imperative to help minimize disruption to bird populations worldwide.
Conclusion
Birds around the world already face an array of human-caused threats from habitat destruction to pollution to invasive species. Now, climate change is exacerbating many of these existing issues while introducing entirely new pressures from rising seas to shifting seasons. Species with particular ecological needs and limited adaptability appear most at risk and require focused conservation intervention. While the challenges are steep, strategic conservation centered around protecting and connecting critical habitats can help enable more birds to withstand the changes ahead. But slowing the pace of climate change through rapid decarbonization of the global economy remains the most important act we must take to give birds the time they need to adjust to the unavoidable shifts coming their way.